--- 1/draft-ietf-dnsext-insensitive-01.txt 2006-02-04 23:10:44.000000000 +0100 +++ 2/draft-ietf-dnsext-insensitive-02.txt 2006-02-04 23:10:44.000000000 +0100 @@ -1,18 +1,18 @@ INTERNET-DRAFT Donald E. Eastlake 3rd Clarifies STD0013 Motorola Laboratories Expires August 2003 February 2003 Domain Name System (DNS) Case Insensitivity Clarification ------ ---- ------ ----- ---- ------------- ------------- - + Donald E. Eastlake 3rd Status of This Document Distribution of this document is unlimited. Comments should be sent to the DNSEXT working group at namedroppers@ops.ietf.org. This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026. Internet-Drafts are @@ -31,27 +31,29 @@ The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. Abstract Domain Name System (DNS) names are "case insensitive". This document explains exactly what that means and provides a clear specification of the rules. This clarification should not have any interoperability consequences. +Copyright (C) 2003 The Internet Society. All Rights Reserved. + INTERNET-DRAFT DNS Case Insensitivity Acknowledgements The contributions to this document of Rob Austein, Olafur - Gudmundsson, Daniel J. Anderson, Alan Barrett, and Andrew Main are - gratefully acknowledged. + Gudmundsson, Daniel J. Anderson, Alan Barrett, Dana, Andrew Main, and + Scott Seligman are gratefully acknowledged. Table of Contents Status of This Document....................................1 Abstract...................................................1 Acknowledgements...........................................2 Table of Contents..........................................2 1. Introduction............................................3 @@ -137,21 +139,21 @@ octets, the first octet having the value of the first three digits considered as a decimal number and the second octet being the character code for the fourth decimal digit. Octets, other than those corresponding to the ASCII digits 0 through 9, can also be protected from recognition, so that they will be treated as a normal label character, by a second convention: preceding them with a back-slash. This is the most commonly used technique for protecting back slash ("\") and period ("."). However, it is advisable to avoid using this on other than printing ASCII - characters. + characters to avoid implementation difficulties. 2.2 Example Labels with Escapes The first example below shows embedded spaces and a period (".") within a label. The second one show a 4 octet label where the second octet has all bits zero and the third octet has all bits one. Donald\032E\.\032Eastlake\0323rd.example. or a\000\255z.example. @@ -209,21 +211,21 @@ As described in [STD 13] and [RFC 2929], DNS has an additional axis for data location called CLASS. The only CLASS in global use at this time is the "IN" or Internet CLASS. The handling of DNS label case is not CLASS dependent. 3.2 Extended Label Type Case Insensitivity Considerations DNS was extended by [RFC 2671] to have additional label type numbers - available. (The only such type defined so far it the BINARY type [RFC + available. (The only such type defined so far is the BINARY type [RFC INTERNET-DRAFT DNS Case Insensitivity 2673].) The ASCII case insensitivity conventions, or case folding, only apply to ASCII labels, that is to say, label type 0x0, whether appearing directly or invoked by indirect labels. 4. Case on Input and Output @@ -248,38 +250,38 @@ comparison specified above is done. Thus such optimization MAY destroy the output preservation of case. This type of optimization is commonly called "name compression". 4.2 DNS Input Case Preservation Originally, DNS input came from an ASCII Master File as defined in [STD 13]. DNS Dynamic update has been added as a source of DNS data [RFC 2136, 3007]. When a node in the DNS name tree is created by such input, no case conversion is done and the case of ASCII labels is - preserved if they are for nodes being creted. However, no change is - made in the name label on nodes that already exist is the DNS data + preserved if they are for nodes being created. However, no change is + made in the name label on nodes that already exist in the DNS data being augmented or updated. It is quite common for higher level nodes to already exist. For example, if data with owner name "foo.bar.example" is input and then later data with owner name "xyz.BAR.example" is input, the name of the label on the "bar.example" node, i.e. "bar", is not changed to "BAR". Thus later retrieval of data stored under "xyz.bar.example" in INTERNET-DRAFT DNS Case Insensitivity this case can easily result is obtaining data with "xyz.BAR.example". - The same considerations apply inputting multiple data records with - owner names differing only in case. From the example above, if an "A" - record is stored under owner name "xyz.BAR.example" and then a second - "A" record under "XYZ.BAR.example", the second will be stored at the - node with the first (lower case initial label) name. + The same considerations apply when inputting multiple data records + with owner names differing only in case. From the example above, if + an "A" record is stored under owner name "xyz.BAR.example" and then a + second "A" record under "XYZ.BAR.example", the second will be stored + at the node with the first (lower case initial label) name. Note that the order of insertion into a server database of the DNS name tree nodes that appear in a Master File is not defined so that the results of inconsistent capitalization in a Master File are unpredicatable output capitalization. 4.3 Wildcard Matching There is one additional instance of note, which reflects the general rules that output case reflects input case unless there is @@ -378,11 +380,11 @@ Milford, MA 01757 USA Telephone: +1 508-851-8280 (w) +1 508-634-2066 (h) EMail: Donald.Eastlake@motorola.com Expiration and File Name This draft expires August 2003. - Its file name is draft-ietf-dnsext-insensitive-01.txt. + Its file name is draft-ietf-dnsext-insensitive-02.txt.